Research On PAPR Reduction Methods For DFT-S-OFDM

In the uplink of LTE, the higher PAPR makes the power consumption of the amplifier higher, and results in the higher cost of the user terminal equipment, and the battery capacity limits its service time. Otherwise, the higher PAPR seriously affects other performances of the system. Because well-focused LTE had selected DFT-S-OFDM as the basic uplink transmission scheme, PAPR reduction methods for DFT-S-OFDM system were studied in this thesis.The pre-distortion technology and the probability technology of PAPR reduction were mainly researched in this thesis. RCF method andμ-law companding method belong to the pre-distortion technology of PAPR reduction. They reduce PAPR obviously, and sacrifice other aspects of performance of the system (such as outband radiation and BER performance degradation). The probability technology of PAPR reduction mainly includes SLM method or PTS method. SLM method was compared with PTS method in the same DFT-S-OFDM system. After simulating and analyzing, the performance of PAPR reduction of PTS method is better than that of SLM method in the same complexity.An improved method based on single tone reservation method was proposed in the thesis. To improve PAPR reduction performance of original method and reduce PAPR of the system, the fixed magnitude of the time domain PAPR reduction signals of original method was changed by the proposed method, and the more appropriate magnitude of the time domain PAPR reduction signals based on magnitudes and phases of actual data was found by the proposed method. When the proposed method was being used, there is non-affection of BER performance and non-side-information. Simulation in DFT-S-OFDM system demonstrated that PAPR reduction performance of the proposed method was better than that of the original approach.